Advancements in neutron resonance analysis system development for fissile material quantification in safeguards applications

Rossi, F.  ; Lee, J. ; Yoshimi, Yuki*; Shiba, Tomooki  ; Terada, Kazushi*; Hori, Junichi*

The Japan Atomic Energy Agency is developing a non-destructive system to detect fissile nuclear materials within a sample combining resonance analysis from prompt fission neutrons, capture gamma-rays, and transmitted neutrons. The detection setup includes an array of plastic scintillators at the sample and a downstream Li scintillator. Recent improvements focus on better neutron/gamma discrimination using advanced EJ-276D plastic scintillators and optimized pulse shape discrimination analysis. Tests were conducted at the Kyoto University time-of-flight facility with natural and enriched uranium samples. This paper presents the latest design updates and experimental results from the system's development. This work is supported by MEXT under the subsidy for the "promotion for strengthening nuclear security and the like".